Optical viewing and illuminating



- Filed Oct. 8, 1945 1 2 Sheets-Sheet 1 INVENTOR ALB/N A. am /5,42

GUSwUA'LLICH 4 TTQRNEY Patented Aug. 27, 1946 OPTICAL VIEWINGD ILLUMINATING DEVICE Albin A. Gradisar and Gustav E. Guellich; Buf

falo, N. Y., assignors, by mesne assignments, to American Optical Company, Southbridge,

Mass, a voluntary association Application October 8, 1943, Serial No. 505,488

This invention relates to new and improved.

means for forming the contour or profile of articles and more particularly relates to new and improved means for providingillumination during theforming operation.

An object of the invention is to provide new and improved meansfor forming the profile or contour of. objects which makes such forming simpler and more economical.

Another object of the invention is to provide new and improved illuminating means for forming apparatus which facilitates the forming operation and allows more accurate forming of the contours. I

Another object of the invention is to provide new and improved means for illuminating a tool and an area of a work piece in relative position and for viewing said work piece and tool over a considerable area whereby the relative position of said tool and work piece may be adjusted.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings. It will be understood that many changes may be made in the details of construction and arrangement of parts without departing from the spirit of the invention as expressed in the accompanying claim. We, therefore, do not wish to be limited to the exact details of construction and arrangement of parts shown and described as the preferred form has been given by way of illustration only.

Referring to the drawings: I

Fig. 1 is a diagrammatic view, partly in section, showing the apparatus in operative position;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1 looking in the direction of the arrows and showing the tool and work in operative position;

Fig. 3 is a sectional view of the illuminating apparatus shown in Fig. 1 but on an enlarged scale;

Fig. 4 is an end view showing the grinding tool in operative position relative to a round blank; and

Fig. 5 is aview similar to Fig. 4 but showing a work blank similar to that shown in Fig. 1.

In the past, machines for forming the contour or profiles of objects have been provided with viewing means and in some cases with illuminatmeans.

Where the viewing means has been employed without illuminating means it was difllcult if at all possible to view the tool and blank and it was not possible to obtain. a well defined shadow of at least a portion of the blank and tool to allow the operator to guide the tool and work relative lClaim. (cram-2) to each other to form the desired contour or profile on the work blank. Also, where illuminating means has been employed to illuminate the work and. tool, due tothe character of illuminating I means employed it. was not possible to obtain a Well defined image of the tool and blank and it was found necessary to provide a mask on the light source or betweenthe light source and work and then to continue adjusting said mask from time to time as the forming or cutting proceeded, or else to use a different mask as the cutting or forming proceeded, and also necessary to use a, different mask for each object of different contour. to be formed. Such errors inthe image, even though slight, still introduced errors in the size of the finished article.

It will be seen from the above that in order to obtain the proper contour or profile on the object a well defined image thereofmust be obtained, which-is not alwayspossible or feasible by merely adjusting a mask or by providing new masks for the illuminating means as cutting proceeds and for each differently contoured object, such being time consuming and expensive.

It, therefore, is a principal object of this in-- vention to provide new and improved'means or apparatus for forming thecontour or profile of objects wherein uniform illumination will be obtained over the entire illuminated area and a well defined image of the tool and work may be obtained at all times without the necessity of ma ing the light source as necessary with prior art arrangements. g

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views. the apparatus embodying the invention and adapted for carrying out the forming process is shown in Fig. 1 and consists of a viewing microscope which comprises an eyepiece I andan objective between which is positioned the roof prism 3 for directing the image received by the objective 2 into the eyepiece and also for inverting said image.

Aligned with the objective 2 is provided the tubular member 4 containing the window 5.

In alignment with the microscope and adapted to be viewed therethrough is provided the work piece 6, on which the desired contour or profile is to be formed, and the grinding wheel or other. tool I for forming such contour.

For illuminating an area of the work piece and the tool is provided the illuminator 8 which is shown in section in Fig. 3 onan enlarged scale.

This illuminator 8 comprises a tubular body member 9 having the supporting flange l0 secured thereto for securing the illuminator in desired position' on the machine'relative to the tool, work i and microscope.

This flange It] may have bolts extending therethrough for use in securing the illuminator with the microscope as well as the work and tool.

Adjacent the upper end or the tubular-1 6 fmember 9 is provided the telescope objective lens? 1 system H which is corrected for spherica1 aberration, coma and color. lend of said tubular bodymemberttisr provided" V the diaphragm member !2 havingthe circular-.Ll5fishaffi23land the circular work 7 laperture or opening l3 over which is positioned the groundfglass disc l4. l4 may be either colored or clear although we prefer to make the sameof a green glass to avoid fatigue in the eye sighting against the light source through the microscope and also to eliminatethe efiect .of'chromatic aberration. If such disc 14 r is of g reen glass as stated; the light provided by the'illuminator will also be substantially mono-1 chromatic. This glass disc I4 has one surface,

preferably its upper surface 2 ground" but not polished. Behind the disc M- is provided the flampsocKetI-S supporting the lamp I6 and also having the'plug H for connection with a source of current to illuminate the lamp It. The mount EB-for the lamp socket'may be connected to the tubular member 9 by screws orthe like l9 or could be soldered thereto as desired and thesocket i5 is secured in) said mount l8 bymeans of the set screw or the like 20; The body member "9 may be provided'with'slotsl adjacent thelamp' :Hi, asshown; for ventilation purposes.

7 It is pointed out th the objective lens system .I i must; be ofsuch optical construction as to provide substantially parallel light for illuminating at leasta port-ionof the tooland an area of the workpiece; l V

a l In'order to form on the work the desired profile or contour it is necessary that the work and tool be adjustably mounted relative to each other and that the microscope also be adjustably mounted to allow the scanning 'or viewing of a considerable area of the workpiece Without the necessity of stopping the forming operation to readjust the position of the workpiece and tool; In order that the w'ork jahd ft'ool may be observed within a considerablerange it is necessary that' the clear aperture of the objective ll be considerablyin excess of the diameter of the field of' theo-bje'ctiv'e 2, that-is, the clear aperture of the objective l'l' should equal the amount'of travel of the mi croscope and microscop objective '2; Thus the field illuminated" by the illuminator' 8 will be of such'are'a that the microscope may be adjusted through a considerable range and the relative position of 'saidtool and work may be viewed throughisa'id range without the necessity of stop--' ping theforming operation as described above. 7

I It is pointed out that the upper surface 2| of the glass. disc: I d whi'ch is a rough ground surface, as describedt above, is positioned at the focal'point d a ent the op si e w This groundgl'ass disc 1 of the objective lens system II. This arrangeexcessive-diiiraction patterns and yet allow sufiicient light to be provided to the objective H to provide illumination of sufiicient intensity.

of the. type shown in Figs. 1 and 2 and showsthe t'oo1 26 rotated on the shaft 27 relative tothe 20 work blank 28 on which the desired contour or profileistobe formed; 7

' It willnbe'seen by employing the parallel light illuminating arrangement'of thelpresent application that a well defined shadow zone of the same cross section as the contour of the object Will be 1 7 obtained; and therefore any errors in focusing and consequent errors in size will be eliminated;

and that uniform illumination and light'inten- V sity will be obtained over the entire illuminated 3' area;

From the foregoing it'will be seen that we have provided simple, efficient and economical means and'process,for'obtaining all-of the objects and advantages of the invention, v

Having described our invention, we claim? In apparatus for use with a contour forming machine an illuminator for silhouetting a portion of a forming'tool onsaid machine and an adjacent portion of a workpiece also carried 0 thereby andadapted to be profiled by said formingtool; said illuminator comprising an elongated tubular housing, a'telescopeobjective lens syst'cmcarried adjacent and completely enclosing an end of said tubular housing, said lens system being corrected; for spherical aberration and coma,

a fixed partition disposed transversely within said housing intermediate the ends thereof and arranged to divide the interior of the housing into aperture of relatively small diameter as compared to the; diameter of the said lens system formed in said partition inaxial alignment with said lens system, said aperture being located at if, the rear focal point of said lens system, a mono- V chromatic filter within said rear compartment and positioned to overlie said aperture, means for securing said filter in such position; a diffus- In Fig. 4there is shown a circular work piece.

separated? front and rear compartments, an 

